One aspect of this project concerns the effect of surgery on long function. Patients who had pneumonectomy for nonmalignant disease early in life are being followed for 25 years to explore the effects of overinflation and reduction in pulmonary capillary bed on cardiopulmonary function and longevity. Patients with localized emphysema or bullous lung disease are followed in similar fashion to define the natural history of this disease and the indications for, and effects of surgery. Finally, alterations in ventilation/perfusion relationships both after general and thoracic surgery are being investigated by steady state studies of the fate of injected gases of varying solubilities. The second aspect concerns correlation of radiographic appearances with clinical, physiologic and pathologic observations in diffuse infiltrative lung disease. Radiographs are coded according to the ILO/UICC classification with amplification for findings not related to pneumoconiosis, and with additional quantitative and qualitative measurements relating to emphysema. Patients with lung biopsy have been our chief concern. Of equal interest have been consecutive epidemiologic surveys in workers exposed to asbestos. Here our main interest has been early detection. Presently, experimental methods include ultrasound scanning for pleural thickness, quantitative measures for finger clubbing, spectral analysis of breath sounds and x-ray magnification techniques. Recently, we have studied pulmonary disorders that may be without radiographic manifestations.